1. Field of the Invention
The present invention relates to a mobile communication terminal, and more particularly, to a mobile communication terminal and signal receiving method thereof. Although the present invention is suitable for a wide scope of applications, it is particularly suitable for receiving GPS and mobile broadcast signals by preventing interference between radio signals received via a dual band antenna.
2. Discussion of the Related Art
Generally, as standards for mobile broadcasting, there are FLO (forward link only) by Qualcomm, U.S.A., DVB-H (digital video broadcasting-handheld) by Nokia, Europe, and Korean DMB (digital multimedia broadcasting) based on European digital audio broadcasting (DAB). DMB is selected to be explained in the following description. As used herein, the term DMB does not limit the scope of the claims to the Korean standard. Rather, the term DMB is used as a generic indicator of a variety of multimedia services that include both audio data and video data, such as, but not limited to, those services represented by the standards identified above.
DMB describes a broadcasting service that enables appreciation of high quality video and CD-level music at anytime or anywhere. DMB is merging with a current mobile communication technology such that DMB service will be available via a mobile communication terminal.
FIG. 1 is a block diagram of a mobile communication terminal to receive CDMA and DMB signals according to a related art.
Referring to FIG. 1, a mobile communication terminal according to a related art consists of a CDMA-DMB dual band antenna 11 and a DMB antenna 12 to provide CDMA communications and DMB services.
Signals received via the CDMA-DMB dual antenna 11 are selectively switched by a diplexer 13 according to mode selection control signals, respectively. Hence, a CDMA signal is inputted to a radio frequency receiver (RFR) chipset 17 via a CDMA RF path 14, whereas a DMB signal is inputted to a DMB chipset 18 via a first DMB RF path 15. Meanwhile, a DMB signal received via the DMB antenna 12 is inputted into the DMB chipset 18 via a second DMB RF path 16. The DMB chipset 18 selects, based on the path having the better radio sensitivity, which of the two DMB signals is to be used.
Meanwhile, in order for the mobile communication terminal to use a function of GPS (global positioning system) as well as to receive the DMB, the CDMA-DMB dual band antenna 11 is replaced by a CDMA-DMB-GPS triple band antenna to perform triple switching using an SP3T (single pole three-throw) switch and the like or a GPS antenna is independently provided to use.
However, in using the triple band antenna, a primary interference signal between a 1.57 GHz GPS signal and an 824˜896 MHs CDMA signal lies on 2.39˜2.47 GHz to affect a 2.6 GHz DMB satellite signal. And, a primary interference signal between the CDMA and DMB satellite signals lies on 1.78˜1.70 GHz to affect the 1.57 GHz GPS signal.
Moreover, in case of using the GPS antenna independently, the three antennas coexisting in one mobile communication terminal mutually play a role as dipole intervening with each other in radio sensitivity to degrade the radio sensitivity or reception.